Miller posed a series of pointed questions about Bergdahl during Hagel's testimony before the House Armed Services Committee. A senior defense official said last week that Bergdahl, who is being held at a U.S. military medical facility in Germany, is too fragile to answer questions about his alleged desertion. That didn't smell quite right to Miller.

"Mr. Secretary, you keep saying we can't get the facts from Sgt. Bergdahl until he gets home," the congressman said. "Have you ever thought about going to Landstuhl and talking to him there?"

"Well, I don't know how much medical training you had, congressman. I haven't had much. And what we're doing is we are allowing the doctors —" Hagel said before Miller cut him off.

"Why hasn't he been returned to the United States?" Miller asked. "We have seriously wounded soldiers that are returned to the United States almost immediately after they are stabilized."

Miller wondered how long Pfc. Jessica Lynch, whose own capture and rescue during the Iraq War were grossly exaggerated, waited before she returned to the United States.

Hagel thought the questions were loaded, and confronted Miller.

"Congressman, I hope you're not implying anything other than that," Hagel said.

The defense secretary, who pushed back at critics of Bergdahl and the POW's family earlier during the hearing, grew even more tense when Miller tried to talk over him.

"Well, I don't like the implication of the question," Hagel said. "He's being held there because our medical professionals don't believe he's ready until they believe he is ready to take the next step."

Hagel said Bergdahl's experience is considerably different than soldiers who return home with physical injuries.

"This guy was held for almost five years in God knows what kind of conditions," Hagel said. "We do know some of the conditions from our intelligence community, not from, by the way, Bergdahl. This is not just about can he get on his feet and walk to a plane."